Year current US$ 2009 10339499 2010 20486361 2011 19854270 2012 26511802 2013 16758559.000000002 2014 26537316 2015 20717772 2016 15491763 2017 30060831 2018 18848598 2019 24947389 2020 18904904 2021 21773455 2022 22595261